Computrainer vs TACX I-magic

I just made the same decision. I tried the Tacx at La Bicicletta and was impressed. I had my heart set on a CompuTrainer for some time.

Then I started doing my homework and evaluating my needs more closely.

1) The Tacx has some problems with the quality of the fork supports, with some complaints of it snapping. It is partially plastic apparently.

2) The number of courses available for the Tacx is limited and getting a set of new courses from the 3rd party supplier will cost you another U$300 or so (for the whole set) I think.

3) Tacx cannot do the spinscan analysis

4) Technical support appears to be lacking, and some even questioned whether they are continuing with the product.

I really wanted the spinscan. It is true that this is a 'mathematical model' of your stroke, but it is better than the tacx which can do nothing.

I really wanted the variety in the courses (the tacx allows you to build a workout profile with their analyzer, so the pure workout need is met here.) and CompuTrainer has many available (free) and you can build your own at no extra cost.

Finally, the CompuTrainer is apparently more accurate on power measurement. Another key issue for me as this is one need I have. IF my research was accurate, tacx power measurement is to the nearest 10 watts I think.

I ordered my CompuTrainer last week and am expecting it tommorrow.

I hope this message helps others making this choice, I spent hours looking for this response, and even emailed a couple of folks who were users. I joined the tacx i-magic forum (UK based) and read their comments. It was ugly, but may not be representative.

I spoke with four users of CompuTrainer (two who had recently made the same choice as I was making) and all are happy with CompuTrainer.

Kind Regards,
Guru.

Hi Guru,

Thanks for your thorough advice about the Computrainer vs. TACX I-magic. After thinking about my needs/wants, your input and hearing the experience of one other current Computrainer owner, the Computrainer is the leading contender again.

I'm not going to make a decision until after New Year's but the likely result is that I will buy neither! (I bought a cyclocross bike in September, am planning to buy a TT bike in April/May and really need new road shoes & pedals. Realistically, that's already more than my cycling budget for this year!)

djmtoronto

Quoted post said:

Originally posted by djmtoronto

Thanks for your thorough advice about the Computrainer vs. TACX I-magic. After thinking about my needs/wants, your input and hearing the experience of one other current Computrainer owner, the Computrainer is the leading contender again.
djmtoronto

Skip the computrainer and the Tacx. Take a look at the Velodyne:

http://www.velodynesports.com/

This trainer has been around for a decade, and was once marketed by Schwinn. Frontline, the company that developed it, has become Velodyne Sports and has since updated the trainer.

I've owned a Velodyne for a while, and I've also owned (briefly, until I sent it back) a Computrainer. There is no comparison insofar as the actual trainer hardware goes. The Velodyne is a bigger, heavier unit, with a 20lb flywheel, that offers resistance up to 1400 watts. It has numerous exercise modes -- constant workload, constant grade, heartrate zone (with integrated sensor that is compatible with Polar Heartrates Montors) -- as well as good race simulations on preprogrammed courses. It also doubles as a scientifically accurate ergometer, and is still used in many exercise physiology labs. With a separate ROM chip, vailable form Velodyne, it does a full array of physical tests such as estimated VO Max, etc. , and it has an interval mode.

By contrast, the Computrainer is just a run-of-the mill foldable trainer that happens to connect to your computer.

Granted, you will not have the pretty 3-D computer graphics offered by Computrainer, but you will have a far better trainer. But, if you want the pretty graphics, you can hook the Velodyne up to your computer and use Netcentric Software.

If you have set aside the cash to purchase a Computrainer, definitely give consideration to the Velodyne as well!

Thanks for the insight.

I just got my CompuTrainer hooked up, so it is a little late to try something else!! It looks good, but there are two things that I wanted that CompuTrainer had and you cannot find BOTH on either the Tacx or Velodyne: Variety of courses (I have been doing ultra-marathon riding so 2-3 hours indoor rides are likely) and the spinscan to check my efficiency.

Ironically, in my first two rides, I was getting an average spinscan number of 94 (!!) but only at 180Watts. Time will tell if this is representative of my ability.

Also, the Velodyne is almost twice the cost of CompuTrainer, and while I think the stand/housing looks way cool, I kind of like the fold-up and put away option for the CT.

Anyway, I learned more today, and I appreciate the link.

Kind Regards,
Guru.

FYI:

The Velodyne does allow you to program your own courses.

Insofar as spinscan, I'm curious about your reaction after you've used it a bit. I thought it's value dubious, and I've heard very mixed things about it.

I have only ridden CompuTrainer twice now, and I am unsure of the value of spinscan, but I perceive it to be useful. I was quite dubious after talking to some folks, now that I have read the manual (just last night), I am less dubious, however my very high numbers need some explaining.

I may update this in a while, because I was desperate for any information when I made my choice.

One thing that I find interesting is that I didn't run into velodyne anywhere (I am in Canada, and don't subscribe to any cycling mags), so I missed it completely. I would have liked to do an analysis of that one as well to be more complete.

It might also be appropriate to compare with the velotron which is also by racermate (CompuTrainer people), but it wasn't in my range for 'convenience'. I don't see a price on that one, but it seems to be more accurate than CompuTrainer. (Wow, just found the price . . . U$6,000, way out of my league).

I think for most people, looking for a trainer, the U$800 Tacx or U$1100 CT PC1 are expensive.

In any case, I will try to provide some input on the spinscan in a few weeks when I have had a chance to use it for a while.

Thanks.

The best trainer by far, especially considering the price, is

www.trainersoftware.com

This has only been out for under a month but tops anything done by any of the other trainers. It's not well used yet but give it another few months it will start to become the industry standard.

Is there hardware required? This could be interesting for those who want to retrofit their existing trainer.

One thing that I learned a lot about during the purchase of trainers, is calibration. How does this technology handle calibration?

Thanks.

does the trainersoftwear do any watts control? This is what will become the industry standard!

I would go with the Tacx i-magic & spend the extra money saved on a Powertap or Ergomo as neither trainer is accurate. As for the limited routes for the i-magic email me off list with your address & will show you something that will blow your mind! Imagine riding up the Col du Galibier & feeling every change in grade & seeing every bush & bend!

Phil TurboVids

As promised, I hereby report on SpinScan!!

At the insistence of my coach, I don't use the spinscan very often, as it is a sure way to mess up a workout, but I have used it and I find it to be very helpful.

Originally I posted spinscan numbers in the 90's, that was my angle of attack or whatever it is called (ATA). My spinscan number is usually 68-72 and my power is almost completely balanced between L/R.

More importantly, when I change my pedal stroke in the slightest, I can see the results immediately in the spinscan. This is particularly interesting in the polar graph, when I have a very serious, but small deadspot at the top of my stroke. Just a small push at the top, and it smooths out. I can only do this for a couple of minutes right now, because that muscle simply doesn't work yet, but I can see the change in the graph almost instantly.

I do believe that spinscan works, and I am glad that I got it.

Kind Regards,
Guru.

Quoted post said:

Originally posted by Guru_2_u_2
. My spinscan number is usually 68-72 and my power is almost completely balanced between L/R.

More importantly, when I change my pedal stroke in the slightest, I can see the results immediately in the spinscan. This is particularly interesting in the polar graph, when I have a very serious, but small deadspot at the top of my stroke.

Are you sure that "smoothing out" that plot and improving those numbers will make you go faster not slower?

The thing is that nobody knows what your optimal pedal stroke looks like in any detail and it may not make much difference anyway.

Quoted post said:

Just a small push at the top, and it smooths out. I can only do this for a couple of minutes right now, because that muscle simply doesn't work yet, but I can see the change in the graph almost instantly.

There are plenty of muscles you could force to work harder with a set of Powercranks. Whether that is a good thing or not is a matter that hasn't been settled (probably because the effects, positive or negative, are small).

***Are you sure that "smoothing out" that plot and improving those numbers will make you go faster not slower?

No. Not at all, and certainly not immediately, but the whole point of a good pedal stroke is to be able to call on more muscle fibres to maintain speed/power. This doesn't happen overnight.

***The thing is that nobody knows what your optimal pedal stroke looks like in any detail and it may not make much difference anyway.

Technically this is not true, an optimal pedal stroke delivers consistent power throughout 360 degrees. Of course, this is not possible, and I get your point. Time will tell. I have good metrics to baseline my performance, and I can tell you that after two weeks on Computrainer, I am stronger. I may not have a better pedal stroke though.

***There are plenty of muscles you could force to work harder with a set of Powercranks. Whether that is a good thing or not is a matter that hasn't been settled (probably because the effects, positive or negative, are small).

Again, I agree with you, but having the option to choose as opposed to hammering away mindlessly is very important to my psychologically. I am glad that I made that choice.

The whole point of my post is that I promised that I would provide the feedback, because I could not find a decent review by a real cyclist ANYWHERE. This looks like a good forum to do so. Take my opinion for what it's worth.

Thanks for your input. I would love to hear other's experiences, because I am still too new to this equipment to know if I am wasting my time.

Kind Regards,
Guru.

Quoted post said:

Originally posted by Guru_2_u_2
an optimal pedal stroke delivers consistent power throughout 360 degrees.

This is a myth, born of incomplete understanding of muscle physiology/biomechanics.

Quoted post said:

Originally posted by acoggan
This is a myth, born of incomplete understanding of muscle physiology/biomechanics.

just to add a bit to Andy's above comment, when examining the pedal force characteristics of two groups of cyclists (elite and state level) the better cyclists generated more pedal force on the downstroke and less on the upstroke than the state level cyclists who generated more force on the upstroke (and less on the downstroke). the only place this may be an advantage is for off-roaders who often have to ride off road (!) up steep slippy climbs and generating large amounts of force on the downstroke may cause the rear wheel to spin.

ric

Quoted post said:

Originally posted by acoggan
This is a myth, born of incomplete understanding of muscle physiology/biomechanics.

It's not a myth. It is simply a fact that if you could deliver consistent power (even less than optimal, say 250W) through 360 degrees, you would probably rival the best cyclists in the world.

To reiterate, I get your point (and ric's) and it is correct. The goal of having a perfect pedal stroke is not necessarily helpful. However any cyclist of note will tell you that pedalling squares is not as easy as 'a more efficient' pedal stroke.

Back to your point, we agree that this is an unknown. However, I had no clue what my stroke looked like two weeks ago. Now I do. I can see a small dead-spot on my left side, and I can attempt to 'fix' it and see if that improves my performance.

This is an intelligent way to improve performance, with metrics which allow me to evaluate the results. Plain and simple.

Thanks for listening.

[QUOTE]Originally posted by Guru_2_u_2
[B]It's not a myth. It is simply a fact that if you could deliver consistent power (even less than optimal, say 250W) through 360 degrees, you would probably rival the best cyclists in the world.
[/quote]

if you wanted to 'rival' the best cyclists in the world (assuming we're talking about endurance based ones), you'd need more like 450 W and to have a mass of just under 70 kg.

i'll reiterate, just pedal the bike and don't worry how you are pedalling, it's not important. all that's important is to increase your power output that you can sustain over the duration of your goal/event/etc.

ric

Quoted post said:

Originally posted by ricstern
...just pedal the bike and don't worry how you are pedalling, it's not important. all that's important is to increase your power output that you can sustain over the duration of your goal/event/etc.

ric

Makes sense to me.

Does this also apply to cadence? Just go with what's comfortable, rather than always striving to spin at a higher cadence?

djmtoronto,
If you don't already have one, I would suggest getting a power meter to use with your rollers or trainer. I can recommend the Powertap Pro, but I hear the Ergomo is good, or the SRM Pro if you find a great deal. The indoor trainers are limited to indoors. You can use the power meter to turn your rollers/wind loader or your trainer into a cheap ergometer and train outdoors with it, too. A PowerTap is no more expensive and you can get another receiver for an extra $50 for a second bike if you have one.
It's easy to keep power output close to target range because the resistance is constant at constant speed. For example, I can keep power between 190 and 210 Watts at all times while trying to stay at 200; I just keep the speed constant. It's easy to keep the average within 1 or 2 Watts of where you want it.
If money is no object, get both a power meter and CT or Tacx. Still, I would start with the power meter since it's so versatile. It's amazing what you learn from it, especially when you read good info from guys like Andy Coggan, Ric Stern, etc.

P.S. get CyclingPeaks Software for another $75 and you'll have it all